Method of installing liner assembly for pipeline repair or reinforcement, and liner assembly and steam generator for same

ABSTRACT

A method of installing a liner assembly for pipeline repair or reinforcement includes: pulling a prepared liner assembly into position in the pipeline, the liner assembly including an outer tubular liner and an inner inflatable bladder positioned longitudinally within the tubular liner, the tubular liner being wetted with a curable compound; introducing fluid into the inflatable bladder so that the inflatable bladder expands to bring the tubular liner into firm contact with an interior surface of the pipeline; flowing the fluid continuously through the bladder and discharging the fluid into the pipeline, while maintaining the liner assembly in an inflated condition for a time period sufficient for the tubular liner to cure; and deflating the inflatable bladder and retrieving at least a portion of the liner assembly from the pipeline.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/675,750 filed on May 23, 2018, U.S. Provisional Application No.62/678,527 filed on May 31, 2018, and U.S. Provisional Application No.62/808,210 filed on Feb. 20, 2019, the contents of which areincorporated herein by reference in their entireties.

FIELD

The subject application generally relates to pipeline repair and/orreinforcement and in particular, to a method of installing a linerassembly for pipeline repair or reinforcement, and to a liner assemblyand a steam generator for use with the same.

BACKGROUND

Liners are commonly used to repair and/or reinforce ruptured or weakareas in pipeline networks such as sewer systems and the like.Conventional approaches for installing a liner into a pipeline typicallyinvolve excavation to expose the pipeline. However, as will beappreciated, excavation methods are expensive, time consuming anddisruptive.

To avoid the problems associated with excavation, “cure-in-place”pipeline repair technology has been developed to allow pipelines to berepaired or reinforced without requiring disruptive excavation. During“cure-in-place” pipeline repair or reinforcement, a resin impregnatedliner is delivered to the pipeline section to be repaired or reinforced,is brought into contact with the interior surface of the pipelinesection and is maintained in place at that location until the curingprocess is complete.

Several approaches for positioning “cure-in-place” liners within apipeline are used in the industry. For example, the liner can be pushedalong the pipeline to a desired location using a series of push-rods. Aswill be appreciated, transitional areas along the pipeline such as bendsand fittings create significant delivery problems, as the push-rods maybe unable to effectively move beyond these transitional areas.

Alternatively, and more commonly used in the industry, the liner may bepulled along the pipeline to a desired location using a winch and cable.For example, U.S. Pat. No. 6,691,741 to Manners discloses aninstallation assembly for installing a liner in a pipeline comprising aninner bladder having an installation end and a retrieval end. An outerbladder surrounds the inner bladder. The ends of the inner and outerbladders are coupled together adjacent the installation end. The innerbladder is coupled to an air source at the retrieval end and the outerbladder adjacent the retrieval end is free. Following installation andcuring of the liner, the bladder assembly is retrieved by pulling on theretrieval end of the inner bladder, and upon retrieval, the outerbladder is inverted.

Inversion delivery, wherein a liner is unrolled through itself byapplied pressure as it projects forwardly into a pipeline, has also beendescribed. For example, U.S. Pat. No. 4,328,012 to Wood discloses amethod of impregnating the inner absorbent layer of a long flexible tubewith a curable resin. During the method, a mass of the resin isintroduced into one end of the tube. A window is formed in theimpermeable outer layer of the tube at a distance from the resin mass. Avacuum in the interior of the tube is drawn through the window andconcurrently the resin mass is pushed toward the evacuated region bypassing the tube between a pair of squeezing members. When the flowingresin reaches the vicinity of the window, the window is sealed. Anotherwindow is formed in the tube farther downstream of the previously formedwindow. A vacuum is drawn through the new window while the squeezingmembers force the resin to flow toward the newly evacuated region. Theprocedure is repeated until the resin has spread through the entireinner absorbent layer of the tube.

Improvements are generally desired. It is therefore at least an objectto provide a novel method of installing a liner assembly for pipelinerepair or reinforcement, and a novel liner assembly and a novel steamgenerator for use with same.

SUMMARY

In one aspect, there is provided a method of installing a liner assemblyfor pipeline repair or reinforcement, the method comprising: pulling aprepared liner assembly into position in the pipeline, the linerassembly including an outer tubular liner and an inner inflatablebladder positioned longitudinally within the tubular liner, the tubularliner being wetted with a curable compound; introducing fluid into theinflatable bladder so that the inflatable bladder expands to bring thetubular liner into firm contact with an interior surface of thepipeline; flowing the fluid continuously through the bladder anddischarging the fluid into the pipeline, while maintaining the linerassembly in an inflated condition for a time period sufficient for thetubular liner to cure; and deflating the inflatable bladder andretrieving at least a portion of the liner assembly from the pipeline.

The fluid may comprise a mixture of steam and air. The method mayfurther comprise heating the air prior to combining the air with thesteam. The method may further comprise increasing a temperature of theinflatable bladder and the tubular liner by increasing a flow rate offluid through the liner assembly in the inflated condition. Increasingthe flow rate may comprise one or both of: increasing pressure of thefluid introduced into the inflatable bladder; and increasing a dischargerate of the fluid into the pipeline. Increasing the discharge rate ofthe fluid into the pipeline may comprise reducing a release pressuresetting of a pressure relief valve connected to an end of the inflatablebladder.

The time period may comprise: a first time period during which a firstfluid is flowed through the bladder, the first fluid being a steam-airmixture, and a second time period during which a second fluid is flowedthrough the bladder. The second fluid may be air at ambient temperature.The second fluid may comprise no steam or less steam than the firstfluid. The hardness of the tubular liner may increase during the secondtime period. The temperatures of the inflatable bladder and the tubularliner may decrease during the second time period.

In another aspect, there is provided a liner assembly for a pipelinesection, the liner assembly comprising: an outer tubular liner; an innerinflatable bladder positioned longitudinally within the tubular liner;an inflation block connected to a first end of the inflatable bladder,the inflation block having a nozzle for receiving a fluid comprisingsteam; and a pull block connected to a second end of the inflatablebladder, the pull block having a fluid discharge outlet.

The fluid may further comprise heated air. The heated air may be heatedprior to being combined with the steam.

The fluid discharge outlet may be configured to discharge the fluid intothe pipeline.

The fluid discharge outlet may be a pressure relief valve. The pressurerelief valve may be an in-line pressure relief valve.

The pull block may be configured to be connected to a winch cable, ahose, or other means for pulling the liner assembly through thepipeline. The fluid discharge outlet may be an in-line pressure reliefvalve comprising one or more holes for connection to the winch cable,the hose, or the other means for pulling the liner assembly through thepipeline.

The inflatable bladder may have a longitudinal over-expansion inhibitingelement therein. The longitudinal over-expansion inhibiting element maybe a longitudinally extending strap.

The liner assembly may further comprise radial over-expansion inhibitingstructure. The radial over-expansion inhibiting structure may comprisesleeves adjacent opposite ends of the liner assembly.

In another aspect, there is provided a steam generator for use with aliner assembly for pipeline repair or reinforcement, the steam generatorcomprising: a water heater configured to heat water to generate steam; awater feed conduit configured to convey water to the water heater; anair heater configured to generate heated air; an air supply conduitconfigured to convey pressurized air to the air heater; a heated airsupply conduit configured to convey heated air from the air heater tothe water heater to yield a steam-air mixture; and an output conduitconfigured to convey the steam-air mixture from the water heater.

The steam generator may further comprise a flow meter in fluidcommunication with the air supply conduit. The flow meter may beconfigured to output a signal indicating a flow rate of the pressurizedair.

The steam generator may further comprise a regulator valve for adjustinga pressure of the pressurized air.

The steam generator may further comprise a temperature sensor or atemperature gauge in thermal communication with the output line.

The steam generator may be portable. The steam generator may be sized tobe transported by a single individual.

The steam generator may be powered by AC electrical mains. The waterheater may comprise one or more electrically-powered heating elements.The air heater may comprise one or more electrically-powered heatingelements.

In another aspect, there is provided a method of installing a linerassembly for pipeline repair or reinforcement, the method comprising:pulling a prepared liner assembly into position in the pipeline, theliner assembly including an outer tubular liner and an inner inflatablebladder positioned longitudinally within the tubular liner, the tubularliner being wetted with a curable compound; introducing fluid into theinflatable bladder so that the inflatable bladder expands to bring thetubular liner into firm contact with an interior surface of thepipeline; flowing the fluid continuously through the bladder anddischarging the fluid into the pipeline, while maintaining the linerassembly in an inflated condition; measuring a flow rate and atemperature of the fluid entering the bladder; calculating a time periodsufficient for the tubular liner to cure based on: an amount of totalheat required for curing, based on dimensional information of a liner,and the measured flow rate and the measured temperature of the fluid;and maintaining the liner assembly in an inflated condition for the timeperiod sufficient for the tubular liner to cure.

The method may further comprise deflating the inflatable bladder andretrieving at least a portion of the liner assembly from the pipeline.

The measuring may further comprise measuring the flow rate and thetemperature of the fluid using a temperature sensor and a flow ratemeter, and wherein the calculating is carried out by processingstructure in communication with the temperature sensor and the flow ratemeter.

The method may further comprise: measuring a temperature of the fluidbeing discharged into the pipeline, wherein the calculating of the timeperiod is further based on: a difference between the temperature of thefluid entering the bladder and the temperature of the fluid beingdischarged into the pipeline.

The curable compound may be an epoxy, and the calculating of the timeperiod is further based on curing properties of the epoxy.

In another aspect, there is provided an automated steam generator systemfor use with a liner assembly for a pipeline section, the systemcomprising: a steam generator configured to flow a steam-air mixturecontinuously through a bladder of the liner assembly inflated within thepipeline, the bladder being positioned within a tubular liner wettedwith a curable compound, the steam generator comprising: a temperaturesensor measuring a temperature of the steam-air mixture entering thebladder, and a flow rate meter measuring a flow rate of the of thesteam-air mixture entering the bladder; and a computing device incommunication with the steam generator and comprising: processingstructure, and memory in communication with the processing structure andstoring computer-readable code comprising instructions which, whenexecuted by the processing structure, cause the computing device to:calculate a time period sufficient for the tubular liner to cure basedon: an amount of total heat required for curing, based on dimensionalinformation of a liner, and the measured flow rate and the measuredtemperature of the fluid; and control the steam generator to flow thesteam-air mixture through the bladder for the time period sufficient forthe tubular liner to cure.

The system may further comprise an additional temperature sensormeasuring a temperature of the fluid being discharged into the pipeline,and further comprising computer-readable code comprising instructionswhich, when executed by the processing structure, cause the computingdevice to: calculate the time period further based on a differencebetween the temperature of the fluid entering the bladder and thetemperature of the fluid being discharged into the pipeline.

The curable compound may be an epoxy, and further comprisingcomputer-readable code comprising instructions which, when executed bythe processing structure, cause the computing device to: calculate thetime period further based on curing properties of the epoxy.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described more fully with reference to theaccompanying drawings in which:

FIG. 1 is a side view of a liner assembly for pipeline repair orreinforcement;

FIG. 2 is a partially exploded side view of a liner segment forming partof the liner assembly of FIG. 1;

FIG. 3 is a sectional view of a portion of the liner segment of FIG. 2;

FIGS. 4a to 4c are perspective, side and top views, respectively, of apressure relief valve forming part of the liner assembly of FIG. 1;

FIGS. 4d and 4e are sectional views of the pressure relief valve of FIG.4c , taken along the indicated section line;

FIGS. 5a and 5b are perspective views showing installation of a pullblock during assembly of the liner assembly of FIG. 1;

FIGS. 6a to 6c are side views showing installation of a retaining sleeveduring assembly of the liner assembly of FIG. 1;

FIGS. 7a to 7c are perspective, front and side views, respectively, of asteam generator for use with the liner assembly of FIG. 1;

FIG. 7d is a perspective cutaway view of a water heater forming part ofthe steam generator of FIGS. 7a to 7 c;

FIGS. 8a to 8c are side views, partly in section, showing installationof the liner assembly of FIG. 1 into a pipeline to be repaired orreinforced;

FIG. 9 is a schematic view of an automated steam generator system foruse with the liner assembly of FIG. 1;

FIG. 10a is a perspective view of an automated steam generator formingpart of the automated steam generator system of FIG. 9;

FIGS. 10b to 10f are perspective and end views of portions of theautomated steam generator of FIG. 10 a;

FIGS. 11a to 11z are pages presented by an automation application usedby the automated steam generator system of FIG. 9;

FIG. 12 is a graphical plot of flow rate as a function of pressuremeasured for an exemplary liner assembly in an exemplary pipeline; and

FIG. 13 is a graphical plot of flow rate as a function of pipelinediameter measured for an exemplary liner assembly in exemplarypipelines.

DETAILED DESCRIPTION OF EMBODIMENTS

The foregoing summary, as well as the following detailed description ofcertain examples will be better understood when read in conjunction withthe appended drawings. As used herein, an element or feature introducedin the singular and preceded by the word “a” or “an” should beunderstood as not necessarily excluding the plural of the elements orfeatures. Further, references to “one example” or “one embodiment” arenot intended to be interpreted as excluding the existence of additionalexamples or embodiments that also incorporate the described elements orfeatures. Moreover, unless explicitly stated to the contrary, examplesor embodiments “comprising” or “having” or “including” an element orfeature or a plurality of elements or features having a particularproperty may include additional elements or features not having thatproperty. Also, it will be appreciated that the terms “comprises”,“has”, “includes” means “including by not limited to” and the terms“comprising”, “having” and “including” have equivalent meanings.

As used herein, the term “and/or” can include any and all combinationsof one or more of the associated listed elements or features.

It will be understood that when an element or feature is referred to asbeing “on”, “attached” to, “connected” to, “coupled” with, “contacting”,etc. another element or feature, that element or feature can be directlyon, attached to, connected to, coupled with or contacting the otherelement or feature or intervening elements may also be present. Incontrast, when an element or feature is referred to as being, forexample, “directly on”, “directly attached” to, “directly connected” to,“directly coupled” with or “directly contacting” another element offeature, there are no intervening elements or features present.

It will be understood that spatially relative terms, such as “under”,“below”, “lower”, “over”, “above”, “upper”, “front”, “back” and thelike, may be used herein for ease of description to describe therelationship of an element or feature to another element or feature asillustrated in the figures. The spatially relative terms can however,encompass different orientations in use or operation in addition to theorientation depicted in the figures.

Turning now to FIG. 1, a liner assembly is shown and is generallyidentified by reference numeral 20. Liner assembly 20 includes a linersegment 22, which has an installation end 24 at one end thereof and aninflation end 26 at the opposite end thereof. To facilitate positioningof the liner assembly 20 in a pipeline, the installation end 24 isfitted with a pull block in the form of an in-line pressure relief valve30 that enables attachment of a suitable pull mechanism (i.e. a winch).The liner segment 22 is also fitted with an inflation block 32 at theinflation end 26, so as to allow the interior area of the liner segment22 to be inflated. In the embodiment shown, the liner segment 22 islongitudinally folded over itself and bound at a plurality of spacedlocations, in this example at twelve (12) to eighteen (18) inchintervals, using tape 34 or other suitable binding material. The linerassembly 20 further comprises tapered sections 36 formed proximate theinstallation end 24 and the inflation end 26. The longitudinal foldedliner segment 22 and the tapered sections 36 of the liner assembly 20allow the liner assembly 20 to be manipulated and moved to a desiredlocation within the pipeline.

FIGS. 2 and 3 better illustrate the liner segment 22. Liner segment 22is generally provided in stock manufactured lengths, and is preferablyprovided on a roll, with desired lengths being cut from stock. The linersegment 22 is generally dimensioned to suit pipelines ranging from 1½inches up to 12″, but those of skill in the art will appreciate that theliner segment 22 may be dimensioned to accommodate smaller or largerpipeline diameters. As can be seen, liner segment 22 is multi-layered,and comprises a tubular liner 42, an elongate malleable inflatablebladder 44 extending longitudinally through the tubular liner, and alongitudinal over-expansion inhibiting element in the form of anon-stretchable strap 46 positioned within and extending the length ofthe inflatable bladder 44. In this embodiment, the tubular liner 42 isfabricated of a felt material, the inflatable bladder 44 is fabricatedof rubber, and the non-stretchable strap 46 is fabricated of wovennylon. The liner segment 22 further comprises a plastic sheathing 50over the outer surface of the tubular liner 42. In this embodiment, theplastic sheathing 50 has a first longitudinal edge that is configured tooverlap a second longitudinal edge, and the overlap is tack welded forfitting the plastic sheathing 50 to the outer surface of the tubularliner 42. Non-stretchable retaining sleeves 52 and 54 are positionedadjacent opposite ends of the liner segment 22 to inhibit radialover-expansion of the liner assembly 20. In this embodiment, the linersegment 22 also comprises a release plastic 56 positioned between thetubular liner 42 and the inflatable bladder 44.

The pressure relief valve 30 is shown in FIGS. 4a to 4e . The pressurerelief valve 30 has a tubular body 58 defining a flow passagetherethrough that is obstructed by a moveable seal 60. The body 58 hasan inlet 62 and an outlet 64 at opposite ends thereof. Eyelet holes 68are formed in the body 58 adjacent the outlet 64 to enable attachment ofa winch cable, described below. In the interior of the body 58 is anannular base 72, on which is seated a coil spring 74 that provides anopposing force against inward movement of the seal 60. At the inlet 62,the body 58 accommodates an annular rotatable nut 76 abutting an annularsleeve 78 disposed against the seal 60. The rotatable nut 76 has screwthreads (not shown) on an outer surface thereof that engage screwthreads (not shown) formed on an inner surface of the body 58. As willbe understood, the release pressure setting of the pressure relief valve30 may increased by rotating the rotatable nut 76 in a first directionto move the annular sleeve 78 and seal 60 toward the spring 74, and maybe decreased by rotating the rotatable nut 76 in a second direction tomove the annular sleeve 78 and seal 60 away from the spring 74. Inoperation, when the pressure on the inlet side of the seal 60 exceedsthe release pressure setting of the pressure relief valve 30, the seal60 is forced open away from the sleeve 78 and against the opposing forceof the spring 74, permitting flow through the flow passage of the body58 for discharge at the outlet 64.

In use, to repair or reinforce a damaged section of pipeline, therequired length of liner is first determined. In this embodiment, avideo camera connected to a video camera line is inserted into and movedalong the interior of the pipeline. The camera line is marked atpositions corresponding to the ends of the damaged section of pipelineto be repaired or reinforced. To ensure that the liner segment 22adequately covers the interior area of the pipeline to be repaired orreinforced, and to allow the liner segment 22 to be trimmed as neededand to have the appropriate installation gear fitted thereto, an extralength portion is added to each end of the liner segment. In thisembodiment, the extra length portion is approximately equal to 10″ (250mm). A liner segment 22 having an appropriate length is then cut fromstock.

The cut liner segment 22 is then prepared in accordance with FIG. 2.Thus, during preparation, portions of the tubular liner 42 and theplastic sheathing 50 proximate the ends 24 and 26 of the liner segment22 are removed by cutting so as to expose the underlying inflatablebladder 44 and release plastic 56. For smaller diameter liners (up to4″), about 6″ of exposed inflatable bladder is sufficient. For largerdiameter liners, about 9″ of exposed inflatable bladder is sufficient.The tubular liner 42, plastic sheathing 50 and inflatable bladder 44 andthe release plastic 56 are then trimmed to expose a length (i.e. 4″) ofstrap 46 at each of the ends 24 and 26.

To prepare the trimmed liner segment 22 for installation, installationend 24 and inflation end 26 are sealed with suitable installation gear.As shown in FIG. 5a , at installation end 24, the pressure relief valve30 is inserted into the inflatable bladder 44. The inflatable bladder 44in the region surrounding the inserted pressure relief valve 30 issubsequently folded in or cinched (as shown in FIG. 5b ) onto thepressure relief valve 30, ensuring a fit that is sufficiently tight forallowing inflation of the inflatable bladder 44 later in the procedure.During preparation of installation end 24, strap 46 is tightlyincorporated either into the folds of the inflatable bladder 44, or intothe taping used to securely maintain this arrangement at installationend 24, as shown in FIG. 5b . Inflation end 26 is similarly prepared(not shown), substituting inflation block 32 for the pressure reliefvalve 30 of the installation end 24. Similar to installation end 24,strap 46 is tightly incorporated into the folds or taping at inflationend 26.

The ends 24, 26 of the liner assembly 20 are further prepared byinserting, between the release plastic 56 and the inflatable bladder 44,proximate each end 24, 26, the retaining sleeves 52, 54, as shown inFIG. 6a (only end 24 and retaining sleeve 42 are shown). Each retainingsleeve 52, 54 is cut to a length that starts at the front edge of theinstallation gear (i.e. pressure relief valve 30 or inflation block 32)and extends into the liner at least 6″, as shown in FIG. 6b . As shownin FIG. 6c , at each end 24, 26, the retaining sleeve 52, 54 and releaseplastic 56 is folded in, over the taped ends previously prepared, andsecurely taped. Each end 24, 26 is then further secured using suitableclamps 80 to ensure a tight fit around the blocks positioned therein. Inthe embodiment shown, clamps 80 are gear clamps.

With the liner assembly 20 sealed at both ends 24, 26 with theappropriate installation gear, the outer tubular liner 42 is impregnatedwith an appropriate resin (i.e. epoxy). The process of impregnating theouter tubular liner 42 is commonly referred to as “wetting”. In thisembodiment, the outer tubular liner 42 is wetted by delivering resin tothe space between the outer tubular liner 42 and the release plastic 56at one of the ends 24, 26. Rollers (not shown) are then used to move theresin along the length of the tubular liner 42, as is known in the art.To ensure complete wetting of the tubular liner 42, resin can be appliedto both ends 24, 26.

After the tubular liner 42 has been wetted, the plastic sheathing 50 isscored to facilitate migration of the resin out of the tubular liner 42.Contact of the resin with the pipeline being repaired ensures that theliner being installed is fixed in place. The outside surface of theplastic sheathing 50 is then wiped to ensure a clean dry surface.Turning again to FIG. 1, the liner assembly 20 is then longitudinallyfolded and taped at approximately 12″ to 18″ intervals 82 to retain thisfolded arrangement.

To facilitate entry and/or movement of the liner assembly 20 in apipeline, the leading edge of the tubular liner 42 is taped to form atapered configuration 62. A winch cable 84 is attached to pressurerelief valve 30 at installation end 24. In this embodiment, devises 86are used to attach winch cable 84 to the pressure relief valve 30. Aninflation line 88 is attached to inflation block 32 of inflation end 26.

The liner assembly 20 is configured to be inflated by a steam generator,which is shown in FIGS. 7a to 7c and is generally indicated by referencenumeral 90. Steam generator 90 is portable, and is sized to betransported on a push trolley to enable the steam generator 90 to bemoved to and from a job site by a single worker. In the example shown,the steam generator 90 occupies a footprint of thirty-two (32) inches bytwenty-four (24) inches, and has a height of eighteen (18) inches, andhas a weight of about one-hundred (100) pounds.

The steam generator 90 comprises a housing 92 that accommodates abox-shaped water heater 94, which is shown in cutaway view in FIG. 7d .The water heater 94 comprises a container 96 that houses a plurality ofheating elements 98 positioned near the floor of the container 96. Theheating elements 98 are configured to heat water to generate steam. Awater feed conduit 102 is mounted on a side of the housing 92, andconveys water into the top of the container 96. The water feed conduit102 includes a hose connector 104 that is configured to be connected toa source (not shown) of pressurized water. The steam generator 90 alsocomprises a pressurized air input conduit 106 having a port 108 that isconfigured to be connected to a source (not shown) of pressurized air,which in this embodiment is a portable air compressor. The pressurizedair input conduit 106 has a flow meter 110 and a regulator valve 114fitted thereto, with the flow meter 110 being configured to output asignal indicating a flow rate of the pressurized air. A pressure gauge116 is connected to the regulator valve 114 for displaying air pressuredownstream of the regulator valve 114. The regulator valve 114 andpressure gauge 116 are supported by a panel 118 mounted on the housing92, the panel 118 being fabricated of metal sheet or the like. A firstair conduit 122 conveys the pressurized air from the regulator valve 114to an air heater 124, which comprises one or more internal heatingelements (not shown) configured to pre-heat the air. A second airconduit 126 conveys the heated air from the air heater 124 into thewater heater 94, where the heated air is combined with steam generatedby the heating elements 98, which accumulates in the upper volume of thecontainer 96 during operation, to yield a steam-air mixture. Thesteam-air mixture is conveyed out of the water heater 94 through anoutput conduit 128, which has a temperature gauge 132 mounted thereonfor displaying the temperature of the outgoing steam-air mixture. Theoutput conduit 128 has a connector 134 that is configured to beconnected to the inflation line 88.

The steam generator 90 also comprises an electrical cable (not shown)and plug (not shown) that are configured to be connected to AC mains(not shown), for powering the heating elements 98 of the water heater 94and the heating elements (not shown) of the air heater 124. The AC mainsare any of one-hundred and twenty (120) V mains in North America,two-hundred and thirty (230) V mains in Europe, and the like.

FIGS. 8a through 8c show installation of the liner assembly 20 in asection of pipeline P. During installation, the winch (not shown) isused to pull the liner assembly 20 into the pipeline P via a winch cable84, as shown in FIG. 8a . The liner assembly 20 is positioned within thepipeline section to be repaired or reinforced. Once the liner assembly20 is at the desired position, the air compressor and the steamgenerator 90 are operated to supply steam-air mixture through theinflation line 88 connected to inflation block 32. Steam-air mixturesupplied through the inflation line 88 passes through inflation block 32and enters internal reservoir 142 of the inflatable bladder 44. Theinflatable bladder 44 is in turn inflated until the liner assembly 20expands to the point where the tubular liner 42 firmly contacts theinterior surface 144 of the pipeline, as shown in FIG. 8b . Duringinflation, the taped portions of the liner assembly 20 release, allowingthe liner assembly, and surrounding plastic sheathing 50 to expand andcontact the interior surface 144. Once inflated, the pressure in theinternal reservoir 142 increases until the release pressure setting ofthe pressure relief valve 30 is reached, at which point the pressurerelief valve 30 opens and excess pressure is released through thepressure relief valve 30 into the pipeline P, as shown in FIG. 8b . Theliner assembly 20 is then maintained in this inflated condition, withcontinuous flow of steam-air mixture through the internal reservoir 142and through the pressure relief valve 30, for a first time periodsufficient to enable the wetted outer felt tubular liner 42 to cure. Inthis embodiment, the duration of the first time period is calculatedusing the measured temperature of the outgoing steam-air mixture, theambient temperature at the job site, and the lengths of the inflationline 88 and the liner segment 22.

As will be understood, the temperature of the inflatable bladder 44 andthe tubular liner 42 may be increased during operation by increasing theflow rate of steam-air mixture therethrough. This is achievable by oneor both of increasing the pressure of the steam-air mixture introducedinto the inflatable bladder 44 by adjusting the regulator valve 114during use, and increasing the discharge rate of the steam-air mixtureinto the pipeline P by reducing the release pressure setting of thepressure relief valve 30 prior to positioning the liner assembly 20within the pipeline P. The temperature of the inflatable bladder 44 andthe tubular liner 42 may be decreased during operation in an oppositemanner.

In this embodiment, at the end of the first time period, the water feed,the heating elements 98 of the water heater 94, and the heating elementsof the air heater 124 are turned off, and unheated pressurized air(only) at generally ambient temperature is flowed continuously throughthe internal reservoir 142 and through the pressure relief valve 30 fora second time period sufficient to allow the liner assembly 20 to cool.It has been observed during testing that the cured tubular liner 42hardens further during the second time period. In this embodiment, thesecond time period is between about twenty (20) minutes and about thirty(30) minutes.

Following curing of the tubular liner 42, the steam generator 90 isdeactivated and the air-steam mixture within the internal reservoir 142is released through the inflation block 32 and inflation line 88 (seeFIG. 8c ), allowing the inflatable bladder 44 to resume its natural flatstate. Once evacuated, the inflatable bladder is then withdrawn from thepipeline P via winch cable 84, leaving the cured tubular liner 42 inposition within the pipeline.

As will be appreciated, the continuous flow of the steam-air mixturethrough the internal reservoir 142 allows the tubular liner 42 to bemaintained at an elevated temperature during curing, whichadvantageously increases the curing rate of the epoxy impregnating thetubular liner 42. As will be understood, increasing the curing ratereduces the time needed for the tubular liner 42 to cure, which in turnallows a greater number of liners to be installed in a single day by asingle worker or crew, thereby increasing throughput and workerefficiency.

As will be appreciated, the continuous flow of the steam-air mixturethrough the internal reservoir 142 and the pressure relief valve 30allows the temperature of the felt tubular liner 42 to be controlledregardless of the ambient conditions (i.e. temperature and humidity) atthe job site. As will be understood, this advantageously providesconsistency in curing conditions from job site to job site, which inturn simplifies the curing process and renders it less of an “art”, andfacilitates training of new workers. Further, and as will be understood,this advantageously provides consistency in curing conditions fromworker to worker.

Additionally, and as will be appreciated, the continuous flow of thesteam-air mixture through the internal reservoir 142 and the pressurerelief valve 30 advantageously prevents condensation from accumulatinginside of the bladder 44, which would otherwise impede heat transferfrom the flowing steam-air mixture to the tubular liner 42.

As will be appreciated, the use of the pressure relief valve 30 allowsthe steam-air mixture to be discharged directly into the pipeline P. Aswill be understood, this advantageously eliminates the need torecirculate steam within the liner assembly during curing, which wouldotherwise require bulky pull blocks and/or bulky inflation blocks toaccommodate the necessary additional tubing needed for recirculation. Aswill be understood, such bulky pull blocks and/or bulky inflation blockswould otherwise create difficulty during pulling of the liner assemblyinto the pipeline, and during withdrawal of the liner assembly from thepipeline.

As will be appreciated, the steam-air mixture used to cure the tubularliner 44 is relatively light in weight, which advantageously allows theliner assembly 20 to be used to repair or reinforce vertically-orientedsections of pipeline. In contrast, prior art liner assemblies that usehot water to cure prior art tubular liners are not suitable for use invertically-oriented sections of pipeline, due to the weight of thecolumn of hot water.

As will be appreciated, the air heater 124 of the steam generator 90allows the air temperature to be controlled prior to combining withsteam. As will be understood, this feature advantageously providesimproved temperature control of the resulting steam-air mixture, ascompared to prior art systems that use only steam to cure epoxy.

As will be appreciated, the air heater 124 of the steam generator 90enables the steam-air mixture to be generated using less energy to heatthe water to generate steam. As will be understood, this featureadvantageously allows the size of the water heater 94 (and in turn thesize of the steam generator 90) to be reduced, as compared to prior artsteam generators that do not have an air heater for pre-heating air.

As will be appreciated, the small size of the steam generator 90 enablesit to be electrically powered by plugging into AC mains. As will beunderstood, this advantageously allows the steam generator 90 to beoperated indoors, in contrast with prior art gas- or diesel-poweredsteam generators for use with prior art pipeline repair systems.

As will be appreciated, the portability of the steam generator 90 allowsthe steam-air mixture to be generated near to the location of thepipeline to be repaired or reinforced, which advantageously eliminatesthe need for steam to otherwise be generated remotely and/or be conveyedto the location of the pipeline via separate tubing. As will beunderstood, the use of separate tubing for conveying suchremotely-generated steam would otherwise be tedious, and would otherwisecreate a safety hazard for workers at the location of the pipeline.

Although in the embodiment described above, at the end of the first timeperiod, the water feed and water heater are turned off, and pressurizedair (only) is flowed continuously through the internal reservoir andthrough the pressure relief valve for a second time period, in otherembodiments, there may alternatively be no second time period duringwhich only pressurized air flow is flowed.

Although in the embodiment described above, the required length of lineris determined by inserting and moving a video camera connected to avideo camera line along the interior of the pipeline, in otherembodiments, the required length of liner may alternatively bedetermined using other methods.

Although in the embodiment described above, during preparation ofinstallation end, the strap is tightly incorporated into the folds ofthe inflatable bladder or the taping used to securely maintain thisarrangement, in other embodiments, the strap may alternatively be firmlyattached to the pull block, with the inflatable bladder being folded inor cinched in a similar manner as that described above.

Although in the embodiment described above, the ends of the linersegment are sealed around the installation gear in two stages, namely bytaping and by clamping, in other embodiments, each of the ends of theliner segment may alternatively be sealed around the installation gearin any manner so as to achieve substantially sealed ends.

Although in the embodiment described above, the tubular liner isfabricated of a felt material, in other embodiments, the tubular linermay alternatively be fabricated of another material.

Although in the embodiment described above, the non-stretchable strap isfabricated of woven nylon, in other embodiments, the non-stretchablestrap may alternatively be fabricated of woven vinyl. In still otherembodiments, the non-stretchable strap may alternatively be fabricatedof any suitable durable, non-stretchable material.

Although in the embodiment described above, the retaining sleeves arefabricated of woven nylon, in other embodiments, the retaining sleevesmay alternatively be fabricated of woven vinyl. In still otherembodiments, the retaining sleeves may alternatively be fabricated ofany suitable durable, non-stretchable material.

Although in the embodiment described above a strap is employed toinhibit longitudinal over-expansion of the liner assembly and sleevesare employed to inhibit radial over-expansion of the liner assembly,those of skill in the art will appreciate that alternative structure orelements may be employed to achieve this functionality.

Although the installation of the liner assembly has been shown withrespect to a linear section of pipeline, the liner assembly may also beused to install a liner in a bent section of pipeline. The ability ofthe liner assembly to adapt to bends (i.e. 22°, 45°, 90°) is provided bythe malleable nature of the inflatable bladder 44 used in the linerassembly. As the liner assembly is inflated in a transitional area, thebladder not only stretches to accommodate the air pressure containedtherein, but conforms to the bend so as to ensure the resin-impregnatedliner is urged into contact with all surfaces of the transitional area.The inflatable bladder achieves this by allowing variable stretching,i.e. stretching less at the inside edge while stretching more at theoutside edge of the bend. Prior art systems that used woven nylon orvinyl bladder systems could not achieve this variable stretching,ultimately resulting in creases and/or folds being formed in theresin-impregnated and resultant cured liner. Additionally, andadvantageously, the bonded portion of the inflatable bladder (or thefirst inflatable bladder) left in position within the pipeline has beenfound to effectively smoothen any crease and/or fold formed in theresultant cured liner. The reduction and/or elimination of these creasesresults in greater fluid flow in the repaired section and well as areduction in the likelihood of debris retainment and possibleobstruction.

In other embodiments, the steam generator configured to inflate theliner assembly 20 may alternatively be differently configured. Forexample, FIG. 9 shows an automated steam generator system for use withthe liner assembly 20, and which is generally indicated by referencenumeral 220. Automated steam generator system 220 comprises a portable,automated steam generator 222, and a portable computing device 224 thatis in wireless communication with the automated steam generator 222.

The portable computing device 224 is configured to communicate with andoperate the automated steam generator 222 through an automationapplication running on the portable computing device 224. In the exampleshown, the portable computing device 224 is a tablet computer, such asfor example an iPad manufactured by Apple Incorporated, of Cupertino,Calif., and the automation application is a “mobile app”, however itwill be understood that the portable computing device 224 mayalternatively be another kind of computing device, such as for example asmartphone, a laptop personal computer, a notebook computer, a portablemedia player, and the like.

The portable computing device may alternatively be any suitablecomputing device comprising, for example, a processing unit orequivalent processing structure, system memory (volatile and/ornon-volatile memory), other non-removable or removable memory (e.g. ahard disk drive, RAM, ROM, EEPROM, CD-ROM, DVD, flash memory, etc.) anda system bus coupling the various computing device components to theprocessing unit or the equivalent processing structure. The computingdevice may also comprise networking capabilities using Ethernet, WiFi,Bluetooth™ and/or other network formats, to enable access to shared orremote drives, one or more networked computers, or other networkeddevices.

The automation application may comprise program modules includingroutines, object components, data structures, and the like, and may beembodied as computer readable program code stored on a non-transitorycomputer readable medium. The computer readable medium is any datastorage device that can store data. Examples of computer readable mediainclude for example read-only memory, random-access memory, CD-ROMs,magnetic tape, USB keys, flash drives and optical data storage devices.The computer readable program code may also be distributed over anetwork including coupled computing devices so that the computerreadable program code is stored and executed in a distributed fashion.

The automated steam generator 222 may be better seen in FIGS. 10a to 10f. In FIGS. 10b to 10f , electrical wiring has been omitted for ease ofviewing. Automated steam generator 222 is portable and wheeled, and issized so as to be moveable to and from a job site by a single worker.The automated steam generator 222 comprises a wheeled base 228 thatsupports a housing 232 comprising two (2) hinged doors 234, vents 236and a fan 238. The housing 232 accommodates a programmable logiccontroller (PLC) 240, which is in wired communication with a two-hundredand forty (240) V and one-hundred and twenty (120) V combined powersupply module 242, an AC relay bank 244, and a DC relay bank 246. Thecontroller 240 is also in wired communication with a wireless router 248that is configured for wireless communication with the portablecomputing device 224. The wireless router 248 may be, for example, aWi-Fi router configured to communicate using the IEEE 802.11 standards,and in this embodiment the wireless router 248 is a T1-WR810N routermanufactured by TP-Link Technologies Company Limited, of Shenzhen,China, and is plugged into an electrical power bar 250.

The automated steam generator 222 comprises the box-shaped water heater94, which has been described above and with reference to FIG. 7d . Thewater heater 94 comprises the container 96 that houses the plurality ofheating elements 98 positioned near the floor of the container 96. Theheating elements are configured to heat water to generate steam. A waterfeed conduit 252 conveys water into the top of the container 96. Thewater feed conduit 252 includes a hose connector 254 that is configuredto be connected to a source (not shown) of pressurized water. Theautomated steam generator 222 also comprises a pressurized air inputconduit 256 having a port 258 that is configured to be connected to asource (not shown) of pressurized air, which in this embodiment is aportable air compressor. The pressurized air input conduit 256 has anincoming air pressure sensor 262, an incoming air temperature sensor264, an incoming air solenoid valve 266 and an air flow meter 268 fittedthereto. The incoming air pressure sensor 262 and the air flow meter 268are in wired communication with the controller 240, and are configuredto output a signal indicating the incoming air pressure and incoming airflow rate, respectively, to the controller 240. The incoming airtemperature sensor 264 is in wired communication with a thermocoupleconverter 270, which is configured to convert the signal output by thetemperature sensor 264 into a signal between four (4) and twenty (20)mA, and to output this as a temperature signal to the controller 240,with which the thermocouple converter 270 is in wired communication. Theincoming air solenoid valve 266 is operated by a relay in the DC relaybank 246.

The automated steam generator 222 further comprises a bypass solenoidvalve 272 downstream from the air flow meter 268. When the bypasssolenoid valve 272 is open, incoming air is diverted to an outputconduit, which has a connector 274 that is configured to be connected tothe inflation line 88. The bypass solenoid valve 272 is operated by arelay in the DC relay bank 246.

Downstream from the bypass solenoid valve 272, when the bypass solenoidvalve 272 is closed, is a digital air regulator 276 that is in wiredcommunication with the controller 240 and that is configured to regulatethe pressure of the incoming air in accordance with a control signalfrom the controller 240. Downstream from the digital air regulator 276are a hot regulated air solenoid valve 278 and a cold regulated airsolenoid valve 280, which are configured to be operated oppositely andas a pair. When the hot regulated air solenoid valve 278 is closed andthe cold regulated air solenoid valve 280 is open, regulated airdownstream from the digital air regulator 276 is diverted to the outputconduit and through the connector 274, which is configured to beconnected to the inflation line 88. The hot regulated air solenoid valve278 and the cold regulated air solenoid valve 280 are each operated by arelay in the DC relay bank 246.

When the hot regulated air solenoid valve 278 is open and the coldregulated air solenoid valve 280 is closed, regulated air downstreamfrom the digital air regulator 276 is conveyed through a first airconduit into an air heater 282, which comprises one or more heatingelements (not shown) configured to pre-heat the air. The air heater 282is configured to be operated by a relay in the AC relay bank 244.Downstream from the air heater 282 is a second air conduit with a heatedair temperature sensor 284 fitted thereto. The heated air temperaturesensor 284 is in wired communication with the thermocouple converter270, which is configured to output a corresponding temperature signal tothe controller 240.

The second air conduit conveys the heated air from the air heater 282into the water heater 94, where the heated air is combined with steamgenerated by the heating elements 98. The steam accumulates in the uppervolume of the container 96 during operation, and when combined with theheated air from the air heater 282 yields a steam-air mixture. Thesteam-air mixture is conveyed out of the water heater 94 through theoutput conduit, which has an outgoing temperature sensor 286 fittedthereto for measuring the temperature of the outgoing air or steam-airmixture. The outgoing temperature sensor 286 is in wired communicationwith the thermocouple converter 270, which is configured to output acorresponding temperature signal to the controller 240. The outputconduit also has an outgoing pressure sensor 288 fitted thereto. Theoutgoing pressure sensor 288 is in wired communication with thecontroller 240, and is configured to output a signal indicating thepressure of the outgoing air or steam-air mixture to the controller 240.

The automated steam generator 222 also comprises a two-hundred and forty(240) V electrical plug port 290 that is configured to be connected to atwo-hundred and forty (240) V AC mains (not shown), and a one-hundredand ten (110) V plug port 292 that is configured to be connected to aone-hundred and ten (110) V AC mains, each for providing power to thepower supply module 242.

The automated steam generator 222 further comprises an ambienttemperature sensor 294 positioned slightly outside of the housing 232and under the wheeled base 228. The ambient temperature sensor 294 is inwired communication with the thermocouple converter 270, which isconfigured to output a corresponding temperature signal to thecontroller 240. In this embodiment, the automated steam generator 222also comprises a distal end temperature sensor port 296 that isconfigured to have connected thereto a distal end temperature sensor 298positioned at the distal end of the liner assembly 20 adjacent therelief valve 30. In this embodiment, wiring of the distal endtemperature sensor 298 is accommodated in the interior of the inflatablebladder 44. The distal end temperature sensor port 296 is in wiredcommunication with the thermocouple converter 270, which is configuredto output a corresponding temperature signal of the distal endtemperature sensor 298 to the controller 240.

The automated steam generator 222 also comprises a dump line 300 influid communication with the output conduit and having a dump solenoidvalve 302 fitted thereto, and a steam vent line 304 also in fluidcommunication with the output conduit, upstream from the connectionpoint of the bypass line with the output conduit, and having a steamvent solenoid valve 306 fitted thereto. When either the bypass solenoidvalve 272 or the cold regulated air solenoid valve 280 is open, thesteam vent solenoid valve 306 is opened. As air flow bypasses the waterheater 94, any steam generated within the water heater is allowed tovent through the steam vent line 304. The dump solenoid valve 302 andthe steam vent solenoid valve 306 are each operated by a relay in the DCrelay bank 246. The automated steam generator 222 further comprises adrain line 308 in fluid communication with the water heater 94, whichprovides an outlet for water to be drained from the water heater 94after use.

Turning now to the automation application, the automation applicationinstalled on the portable computing device 224 is configured to presenta graphical user interface on a display of the portable computing device224. The graphical user interface comprises a variety of differentpages. In the example shown, the portable computing device 224 is atablet computer and the pages displayed by the graphical user interfaceare generally sized for display on a tablet computer display, however itwill be understood that the automation application displays similarpages that may be differently sized, as appropriate, on other kinds ofcomputing devices.

When launched on the portable computing device 224, the automationapplication displays a start page on the display of the portablecomputing device 224. FIG. 11a shows the start page, which is generallyreferred to using reference numeral 322. The start page 322 comprises anouter controls area 326, in which virtual buttons for controlling theautomated steam generator 222 and indicators showing statuses ofcomponents of the automated steam generator 222 are presented. Thecontrols area 326 is presented on all pages displayed by the automationapplication. In the example shown, the controls area 326 comprises apower button 328 a and a stop button 328 b, each of which may beselected to turn the power supply module 242 on and off, respectively,and a main air button 328 c that may be selected to open or close theincoming air solenoid valve 266. The controls area also comprises aplurality of virtual indicators, which in the example shown include: aregulated cold air indicator 332 a, which is illuminated when the coldregulated air solenoid valve 280 is open; a regulated hot air indicator332 b, which is illuminated when the hot regulated air solenoid valve278 is open; a bypass indicator 332 c, which is illuminated when thebypass solenoid valve 272 is open; a dump indicator 332 d, which isilluminated when the dump solenoid valve 302 is open; two (2)two-hundred and forty (240) V main power indicators 332 e, which areilluminated when two-hundred and forty (240) V power is supplied to thepower supply module 242; a one-hundred and twenty (120) V powerindicator 332 f, which is illuminated when one-hundred and twenty (120)V power is supplied to the power supply module 242; a main powerindicator 332 g; and a main air indicator 332 h, which is illuminatedwhen the incoming air solenoid valve 266 is open.

In addition to the controls area 326, the start page 322 comprises astart button 334 a, which when selected causes the automationapplication to display a login page, and a reset button 334 b, whichwhen selected causes the controller 240 to remove previous data frommemory and to reset the electrical system of the automated steamgenerator 222.

FIG. 11b shows the login page, which is generally indicated by referencenumeral 338. In addition to the controls area 326, the login page 338comprises: a login button 340 a, which when selected opens a text entryfield (not shown) into which an authorized username can be entered by aworker to login to the automation application; a logout button 340 bwhich when selected causes the automation application to logout the userassociated with the username; a back button 340 c which when selectedcauses the automation application to display the previous page; and asensors button 340 d, which when selected causes the automationapplication to display a sensors page. The login page 338 also comprisesa login status banner 340 e, which indicates the permission status ofthe username that is currently logged in. In this embodiment, theavailable permission statuses are “authorized user”, “authorizedsupervisor” and “factory”. In the example shown, the login status banner340 e indicates “access denied”, indicating that no authorized usernameis currently logged in to the automation application.

Entry of an authorized username causes the automation application todisplay an authorized login page, which is shown in FIG. 11c and isgenerally indicated by reference numeral 344. Authorized login page 344is similar to the login page 338, but further comprises a start button346 a, which when selected causes the application to display an addressentry page; a cure liner button 346 b, which when selected causes theautomation application to display a cure selection page; a cooldownbutton 346 c, which when selected causes the automation application torun a cooldown sequence and to display a cooldown page; a clear databutton 346 d, which when selected causes the automation application toerase all address information and pipe information in memory; and a getprevious data button 346 e.

FIG. 11d shows the sensors page, which is generally indicated byreference numeral 348. The sensors page 348 displays a plurality ofanalog gauges 352 a and numerical value fields 352 b for the sensors ofthe automated steam generator 222. In the example shown, the sensorsrepresented are: temperature of the outgoing flow, as measured by theoutgoing temperature sensor 286 (“machine temp out”); the temperaturedownstream of the air heater, as measured by the heated air temperaturesensor 284 (“heater 2 temp”); the pressure inside the malleableinflatable bladder 44, as measured by the outgoing pressure sensor 288(“bladder pressure”); the temperature adjacent the relief valve 30, asmeasured by the distal end temperature sensor 298 (“pull end exittemp”); the air flow rate, as measured by the air flow meter 268 (“airflow”); and the ambient temperature, as measured by the ambienttemperature sensor 294 (“ambient temp”). The sensors page 348 alsocomprises the back button 340 c, and a diagnostics button 352 c, whichmay be selected to cause the automation application to display adiagnostics page.

FIG. 11e shows the diagnostics page, which is generally indicated byreference numeral 354. The diagnostics page 354 comprises a plurality ofvirtual buttons 356 a that when selected cause the automationapplication to control the automated steam generator 222 to activate anddeactivate a specific solenoid valve and its associated relay, fortesting purposes. In the example shown, the virtual buttons includebuttons for activating and deactivating each of: air heater 282 (“heater2”); the dump solenoid valve 302 (“dump”); the bypass solenoid valve 272(“bypass”); the hot regulated air solenoid valve 278 (“hot reg′ d”); andthe cold regulated air solenoid valve 280 (“cold reg′ d”). Thediagnostics page also comprises a factory settings button 356 b, whichmay be selected to display factory settings pages.

FIGS. 11f to 11h show the factory settings pages, which are generallyindicated by reference numeral 360. Factory settings page 360 displays aplurality of settings 362 a and the values 362 b associated with each ofthe settings 362 a. If the permission status of the username that iscurrently logged in is “factory”, then each of the values 362 b may beselected to open a text entry field (not shown) into which a value canbe entered by a user. Otherwise, if the permission status of theusername that is currently logged in is “authorized user” or “authorizedsupervisor”, the values 362 b cannot be changed. The factory settingspages 360 comprise the back button 340 c and a next button 362 c, whichmay be selected to navigate between factory settings pages 360, andbetween the factory settings pages 360 and the diagnostics page 354. Thefactory settings pages 360 also comprise the sensors button 340 d.

Turning again to FIG. 11c , selection of the start button 346 a causesthe automation application to display an address entry page, which isshown in FIG. 11i and is generally indicated by reference numeral 366.Address entry page 366 comprises a plurality of address fields 368 a,each of which may be selected to open a text entry field (not shown)into which address information associated with the job site may beentered by the user. The address entry page 366 also comprises the backbutton 340 c and the sensors button 340 d, and further comprises thenext button 362 c which, when selected, causes the automationapplication to display a job information page.

FIG. 11j shows the job information page, which is generally indicated byreference numeral 372. Job information page 372 comprises a plurality offields 374 a, each of which may be selected to open a text entry field(not shown) into which job information associated with the job mayentered by the user. The job information page 372 also comprises acuring agent pull-down menu button 374 b which may be selected to allowthe user to select a second epoxy component from a list of possiblesecond epoxy components, and a voltage pull-down menu button 374 c,which may be selected to allow the user to select a voltage from a listof possible voltages. The user input page 372 also comprises the backbutton 340 c and the sensors button 340 d, and further comprises thenext button 362 c which, when selected, causes the automationapplication to display a pipe information input page.

FIG. 11k shows the pipe information input page, which is generallyindicated by reference numeral 376. Pipe information input page 376comprises a plurality of fields 378 a, each of which may be selected toopen a text entry field (not shown) into which dimensional informationassociated with the physical dimensions of the pipe P, the liner 42 andthe inflatable malleable bladder 44 may entered by the user. The pipeinformation input page 376 also comprises a plurality of fields 378 b inwhich a calculated volume of the inflatable malleable bladder 44 isdisplayed. The calculated volume of the inflatable malleable bladder 44is calculated by the automation application using the dimensionalinformation of the inflatable malleable bladder 44 (namely, “pipediameter” and “length of bladder”) entered into the fields 378 a. Thepipe information input page 376 also comprises the back button 340 c andthe sensors button 340 d, and further comprises the next button 362 cwhich, when selected, causes the automation application to display aresin calculation page.

FIG. 11l shows the resin calculation page, which is generally indicatedby reference numeral 382. Resin information page 382 comprises a resincalculation button 384 a, which may be selected to calculate amounts offirst epoxy component, namely unreacted epoxy resin, and second epoxycomponent, namely epoxy curative, to be combined and applied as “resin”to the liner at the job site, based on dimensional information of theliner 42 (namely, “pipe diameter” and “length of liner”) entered intothe fields 378 a. The resin information page 382 also comprises: a totalepoxy amount field 384 b, in which a calculated total amount of epoxycomponents is displayed, based on the dimensional information of theliner 42 entered into the fields 378 a of the pipe information inputpage 376; total component amount fields 384 c, in which calculated totalamounts of the first epoxy component and the second epoxy component aredisplayed, based on the second epoxy component selected using the curingagent pull-down menu button 374 b on the job information page 372; apail number field 384 d, in which a calculated number of pails neededfor mixing the calculated total amount of epoxy components is displayed;and pail component amount fields 384 e, in which calculated amounts ofthe first epoxy component and the second epoxy component needed per pailare displayed. The resin information page 382 also comprises the backbutton 340 c and the sensors button 340 d, and further comprises thenext button 362 c which, when selected, causes the automationapplication to display a bladder test page.

FIG. 11m shows the bladder test page, which is generally indicated byreference numeral 386. The bladder test page 386 comprises a bladdertest button 388 a, which when selected causes the automation applicationto run a bladder inflation sequence for test purposes. During thebladder inflation sequence, the automation application causes theautomated steam generator 222 to open the bypass solenoid valve 272 tofill the inflatable malleable bladder 44 with a volume of aircorresponding to the calculated volume of the inflatable malleablebladder 44, as measured by the air flow meter 268 over an elapsed time.Once the inflatable malleable bladder 44 has been filled, the automationapplication closes the bypass solenoid valve 272 and opens the coldregulated air solenoid valve 280, which passes, unheated regulated airinto the inflatable malleable bladder 44. At this time, the user cangenerally check for leaks and inspect the integrity of inflated linerassembly 20. The bladder test page 386 also comprises a check flowbutton 388 b, which when selected displays the flow rate through theinflated liner assembly 20. At this time, the user can adjust therelease pressure setting of the pressure relief valve 30 at a certainregulated pressure such that the measured flow rate is within a desiredrange, such as between about 6 and about 8 scfm. The bladder test page386 also comprises a forty (40) psi compressed air indicator 388 c; aregulate button 388 d, which when selected allows the user to adjust thepressure setting of the digital air regulator 276; an additionalinflation button 388 e, which may be selected to increase the inflationpressure of the inflatable malleable bladder 44 by a predefined amount;an air dump button 388 f, which when selected causes the automationapplication to close the incoming air solenoid valve 266 and open thedump solenoid valve 302 to release air pressure from the inflatablemalleable bladder 44; and a close dump button 388 g, which when selectedcauses the automation application to close the dump solenoid valve 302.The bladder test page 386 also comprises the next button 362 c which,when selected, causes the automation application to display a liningpage.

FIG. 11n shows the lining page, which is generally indicated byreference numeral 392. Lining page 392 comprises an instructions banner394 a, in which a sequence of instructions to be followed by the user isdisplayed. In the example shown, the sequence of instructions includes“wet out liner”, “install liner” and “connect hose”. The lining page 392also comprises a plurality of indicators 394 b, which in the exampleshown are a temperature over one-hundred fifty (150) F indicator, acompressor over ninety (90) psi indicator, a temperature at one-hundredeighty (180) F indicator, and the compressor under forty (40) psiindicator. The lining page 392 also comprises an ambient temperatureentry field 394 c, which when selected opens a text entry keyboard (notshown) for allowing a user to enter a temperature of the liner 42generally at the time of wetting with epoxy. The temperature of thewetted liner 42 may be measured by a handheld pyrometer (not shown)operated by the user, for example. The lining page 392 comprises theback button 340 c, and also comprises the next button 362 c which, whenselected, causes the automation application to display the cureselection page. The lining page 392 further comprises an inflate button394 d which, when selected, causes the automation application to run thebladder inflation sequence and to display an inflation page.

FIG. 11o shows the inflation page, which is generally indicated byreference numeral 396. The inflation page 396 comprises: a regulatebutton 398 a, which when selected allows the user to adjust the pressuresetting of the digital air regulator 276; an additional inflation button398 b, which may be selected to increase the inflation pressure of themalleable inflatable bladder, an air dump button 398 c, which whenselected causes the automation application to control the automatedsteam generator 222 to close the incoming air solenoid valve 266 andopen the dump solenoid valve 302 to release air pressure from theinflatable malleable bladder 44; and a close dump button 398 d, whichwhen selected causes the automation application to close the dumpsolenoid valve 302. The inflation page 396 also comprises a plurality ofindicators 398 e, which in the example shown are the temperature overone-hundred fifty (150) F indicator, a compressed air under forty (40)psi indicator, and the temperature at one-hundred eighty (180) Findicator. The inflation page 396 also comprises: a required volumedisplay field 398 f, which displays the calculated volume of theinflatable malleable bladder 44; a volume filled display field 398 g, ascalculated by the automation application using the output of the airflow meter 268 over an amount of time elapsed since the beginning of theinflation sequence; a pressure display field 398 h, which displays themeasured pressure in the inflatable malleable bladder 44 as measured bythe outgoing pressure sensor 288; and an elapsed time field 398 i, whichdisplays the amount of time elapsed since the beginning of the inflationsequence. The inflation page 396 also comprises the back button 340 cand the sensors button 340 d, and further comprises a cure liner button398 j, which when selected causes the automation application to displaythe cure selection page.

FIG. 11p shows the cure selection page, which is generally indicated byreference numeral 402. Cure selection page 402 comprises a plurality ofbuttons that prompt the user to select a curing format, with each curingformat having a different amount of automation controlled by theautomation application. In the example shown, the cure selection page402 comprises: an auto cure button 404 a, which when selected causes theautomation application to display an automated cure confirmation page; amanual cure button 404 b, which when selected causes the automationapplication to display a manual cure confirmation page; and an estimatedcure button 404 c, which when selected causes the automation applicationto display an estimated cure confirmation page. The automationapplication displays the auto cure button 404 a and the manual curebutton 404 b for all permission statuses, but displays the estimatedcure button 404 c only for “authorized supervisor” and “factory”permission statuses. The cure selection page 402 also comprises anestimated curing time display field 404 d, in which an estimated curingtime of the liner 42 as calculated by the automation application isdisplayed. The estimated curing time of the liner 42 is calculated bythe automation application using at least: i) a calculated amount oftotal heat required for curing, based on information entered by the userinto the pipe information input page 376, and at least includingdimensional information of the liner 42, and ambient temperature; ii)the flow rate and flow temperature, as measured by the air flow meter268 and the outgoing temperature sensor 286; iii) a calculated amount ofheat loss through the inflation line 88 and the malleable inflatablebladder 44, as indicated by the temperature difference measured by theoutgoing temperature sensor 286 and the distal end temperature sensor298; and iv) the epoxy type, based on information entered by the userinto the job information input page 372, and based on known thermalproperty data and/or standardized cure rate data stored in memory by theautomation application for the first and second epoxy components. Thecure selection page 402 also comprises a data point number display field404 e, which displays the number of data points to be used during theestimated curing time, and data point separation field 404 f, whichdisplays the time between data points. The cure selection page 402 alsocomprises a plurality of indicators 404 g, which in the example shownare the temperature over one-hundred fifty (150) F indicator and thecompressed air under forty (40) psi indicator.

FIG. 11q shows the automated cure confirmation page, which is generallyindicated by reference numeral 406. Automated cure confirmation page 406comprises a message banner 408 a containing a message prompting the userto confirm that he or she wishes to run the automated cure sequence. Theautomated cure confirmation page 406 also comprises a “no” button 408 b,which when selected causes the automation application to redisplay thecure selection page 402, and a “yes” button 408 c, which when selectedcauses the automation application to control the automated steamgenerator 222 to run an automated cure sequence, in which the automationapplication generally utilizes output provided by the outgoingtemperature sensor 286 to continuously adjust the remaining cure time,and to display an automated cure page.

FIG. 11r shows the automated cure page, which is generally indicated byreference numeral 412. Automated cure page 412 comprises a plurality ofdisplay fields, which display information about the automated curesequence being controlled by the automation application. In the exampleshown, the display fields comprise an estimated cure time display field414 a, which displays the estimated curing time originally displayed onthe cure selection page 402; a current cure time display field 414 b, inwhich an adjusted estimated curing time calculated by the automationapplication is displayed. The adjusted estimated curing time of theliner 42 is calculated by the automation application using at least: i)the calculated amount of total heat required for curing, based oninformation entered by the user into the pipe information input page376; ii) an average flow rate and average flow temperature, as measuredby the air flow meter 268 and the outgoing temperature sensor 286 duringthe elapsed portion of the automated cure sequence; iii) an averagecalculated amount of heat loss through the inflation line 88 and themalleable inflatable bladder 44, as measured by the outgoing temperaturesensor 286 and the distal end temperature sensor 298 during the elapsedportion of the automated cure sequence; and iv) the epoxy type, based oninformation entered by the user into the job information input page 372;an elapsed time display field 414 c, which displays the amount of timeof the elapsed portion of the automated cure sequence; and an estimatedtime left display field 414 d, which displays the difference between theadjusted estimated curing time and the elapsed time.

The automated cure page 412 also comprises pull end temperature displayfields 414 e, which display current, average and maximum temperaturesmeasured by the distal end temperature sensor 298 during the elapsedportion of the automated cure sequence; and bladder pressure displayfields 414 f, which display current, average and maximum pressuresmeasured by the outgoing pressure sensor 288 during the elapsed portionof the automated cure sequence. The automated cure page 412 alsocomprises a time extension field 414 g, which may be selected by theuser to enter an amount of additional time by which to extend theautomated curing sequence. The automated cure page 412 also comprises aplurality of indicators 414 h, which in the example shown are thetemperature over one-hundred fifty (150) F indicator, the compressed airunder forty (40) psi indicator, a pull end temperature over seventy-five(75) F indicator, and a pull end temperature over one-hundred (100) Findicator. The automated cure page 412 further comprises a stop heatbutton 414 i, which when selected by the user causes the automationapplication to control the automated steam generator 222 to turn offpower to the air heater 282 and to the heating elements 98 in the tank94.

When the calculated time remaining during the automated curing sequencereaches zero, the automation program displays a cool down button 414 jon the automated cure page 412. Selection of the cool down button 414 jby the user causes the automation application to control the automatedsteam generator 222 to initiate a cooldown sequence, in which i) the hotregulated air solenoid valve 278 is closed and the cold regulated airsolenoid valve 280 is opened such that regulated air bypasses theheaters and is diverted to the output conduit and through the connector274, and ii) power to the air heater 282 and to the heating elements 98in the tank 94 is turned off. Selection of the cool down button 414 j bythe user also causes the automation application to display a cooldownpage.

FIG. 11s shows the manual cure confirmation page, which is generallyindicated by reference numeral 416. Manual cure confirmation page 416comprises a message banner 418 a containing a message prompting the userto confirm that he or she wishes to run the manual cure sequence. Themanual cure confirmation page 416 also comprises a “no” button 418 b,which when selected causes the automation application to redisplay thecure selection page 402, and a “yes” button 418 c, which when selectedcauses the automation application to control the automated steamgenerator 222 to run a manual cure sequence and to display an automatedcure page.

FIG. 11t shows the manual cure page, which is generally indicated byreference numeral 422. Manual cure page 422 comprises the estimated curetime display field 414 a, which displays the estimated curing timeoriginally displayed on the cure selection page 402; an elapsed timedisplay field 424 a, which displays the amount of time of the elapsedportion of the manual cure sequence; and an estimated time left displayfield 424 b, which displays the difference between the estimated curingtime and the elapsed time. The manual cure page 422 also comprises aplurality of display fields 424 c which display the current bladderpressure as measured by outgoing pressure sensor 288; the currentoutgoing temperature as measured by the outgoing temperature sensor 286;the current distal end temperature as measured by the distal endtemperature sensor 298 (if used); and the current flow rate as measuredby the air flow meter 268. The manual cure page 422 also comprises thetime extension field 414 g, which may be selected by the user to enteran amount of additional time by which to extend the manual curingsequence. The manual cure page 422 also comprises a plurality ofindicators 424 h, which in the example shown are the temperature overone-hundred fifty (150) F indicator and the compressed air under forty(40) psi indicator. The manual cure page 422 also comprises the stopheat button 414 i and the cool down button 414 j.

FIG. 11u shows the estimated cure confirmation page, which is generallyindicated by reference numeral 426. Estimated cure confirmation page 426comprises a message banner 428 a containing a message prompting the userto confirm that he or she wishes to run the estimated cure sequence. Theestimated cure confirmation page 426 also comprises a “no” button 428 b,which when selected causes the automation application to redisplay thecure selection page 402, and a “yes” button 428 c, which when selectedcauses the automation application to control the automated steamgenerator 222 to run an estimated cure sequence and to display anestimated cure page.

FIG. 11v shows the estimated cure page, which is generally indicated byreference numeral 432. Estimated cure page 432 comprises the estimatedcure time display field 414 a, which displays the estimated curing timeoriginally displayed on the cure selection page 402; an elapsed timedisplay field 434 a, which displays the amount of time of the elapsedportion of the estimated cure sequence; and an estimated time leftdisplay field 434 b, which displays the difference between the estimatedcuring time and the elapsed time. The estimated cure page 432 alsocomprises a plurality of display fields 434 c which display the currentbladder pressure as measured by outgoing pressure sensor 288; thecurrent outgoing temperature as measured by the outgoing temperaturesensor 286; the current distal end temperature as measured by the distalend temperature sensor 298 (if used); and the current flow rate asmeasured by the air flow meter 268. The estimated cure page 432 alsocomprises the time extension field 414 g, and a plurality of indicators434 d, which in the example shown are the temperature over one-hundredfifty (150) F indicator and the compressed air under forty (40) psiindicator. The estimated cure page 432 also comprises the stop heatbutton 414 i and the cool down button 414 j.

FIG. 11w shows the cooldown page, which is generally indicated byreference numeral 438. Cooldown page 438 comprises an estimated cooldowntime display field 442 a, which displays an estimated cooldown time ofthe liner 42 as calculated by the automation application. The estimatedcooldown time of the liner 42 is calculated by the automationapplication using one or more of: i) a calculated amount of total heatin the liner at the beginning of the cooldown sequence, based oninformation entered by the user into the pipe information input page376; ii) the calculated amount of heat loss through the inflation line88 and the malleable inflatable bladder 44; and iii) the flow rate andflow temperature, as measured by the air flow meter 268 and the outgoingtemperature sensor 286. The cooldown page 438 also comprises: an elapsedtime display field 442 b, which displays the amount of time of theelapsed portion of the cooldown sequence.

The cooldown page 438 also comprises display fields 442 c which displaythe current and average pull end temperatures measured by the distal endtemperature sensor 298 during the elapsed portion of the cooldownsequence; display fields 442 d which display the current, average andmaximum pressures measured by the outgoing pressure sensor 288 duringthe elapsed portion of the cooldown sequence; a display field 442 ewhich measures the current flow rate measured by the air flow meter 268;and display fields 442 f which display the current outgoing and distalend temperatures as measured by the outgoing temperature sensor 286 andthe distal end temperature sensor 298. The cooldown page 438 alsocomprises a time extension field 442 g, which may be selected by theuser to enter an amount of additional time by which to extend thecooldown sequence. The cooldown page 438 also comprises a plurality ofindicators 442 h, which in the example shown are the temperature overone-hundred fifty (150) F indicator and the compressed air under forty(40) psi indicator. The cooldown page 438 also comprises a stop cooldownbutton 442 i, which when selected by the user causes the automationapplication to control the automated steam generator 222 to end thecooldown sequence by closing the incoming air solenoid valve 266 andopening the dump solenoid valve 302 to release air pressure from theinflatable malleable bladder 44, and to display data report pages.

When the amount of time of the elapsed portion of the cooldown sequenceequals the estimated cooldown time of the liner 42, the automationapplication controls the automated steam generator 222 to end thecooldown sequence, and updates the cooldown page 438 to a display a“finish” button (not shown) at the position where the stop cooldownbutton 442 i was previously located. The finish button may be selectedby the user to display the data report pages.

FIGS. 11x to 11z show the data report pages, which are generallyindicated by reference numeral 448. Data report pages 448 comprises aplurality of display fields in which information entered by the user,and acquired sensor data, are displayed. The contents of the data reportpages 448 can be provided as a job summary printout to the customer asproof that the liner 44 was correctly and successfully installed. Thedata report pages 448 comprise a back button 452 a and a next button 452b, which may be selected to navigate between data report pages 448. Thedata report pages 448 also comprises a start new liner button 452 c,which when selected causes the application to display the authorizedlogin page 344.

As will be appreciated, the automation application, in conjunction withthe automated steam generator 222, allows the cure time, the amount ofepoxy, the amount of each epoxy component, and the amount of cooldowntime to be automatically calculated. This advantageously reduces theamount of labor and effort required by the worker, and advantageouslyremoves the likelihood of human error. Additionally, the automaticcalculation of the cure time, the amount of epoxy, the amount of eachepoxy component, and the amount of cooldown time, advantageouslyprovides consistency and standardization in curing conditions i) amongdifferent liner installations; ii) among different job sites; iii) amongdifferent workers; and iv) among different worker organizations and/orlicensees.

As will be appreciated, logging of data by the automation applicationthroughout pre-installation testing and installation of the lineradvantageously allows worker performance to be later reviewed to ensurethat workers are installing liners correctly. Additionally, and as willbe appreciated, the logging of data by the automation applicationthroughout pre-installation testing and installation of the lineradvantageously allows the job summary report to be provided to theclient as a printed report as evidence that the liner was properlyinstalled, such as for quality assurance purposes.

As will be appreciated, the pages presented by the automationapplication are user-friendly and intuitive, and can serve as a visualaid in training new workers about the installation process.

As will be appreciated, and as discussed above for steam generator 90,the continuous flow of the steam-air mixture through the internalreservoir 142 allows the tubular liner 42 to be maintained at anelevated temperature during curing, which advantageously increases thecuring rate of the epoxy impregnating the tubular liner 42. As will beunderstood, increasing the curing rate reduces the time needed for thetubular liner 42 to cure, which in turn allows a greater number ofliners to be installed in a single day by a single worker or crew,thereby increasing throughput and worker efficiency.

Additionally, as will be appreciated, and as discussed above for steamgenerator 90, the continuous flow of the steam-air mixture through theinternal reservoir 142 and the pressure relief valve 30 advantageouslyprevents condensation from accumulating inside of the bladder 44, whichwould otherwise impede heat transfer from the flowing steam-air mixtureto the tubular liner 42.

As will be appreciated, and as discussed above for steam generator 90,the use of the pressure relief valve 30 allows the steam-air mixture tobe discharged directly into the pipeline P. As will be understood, thisadvantageously eliminates the need to recirculate steam within the linerassembly during curing, which would otherwise require bulky pull blocksand/or bulky inflation blocks to accommodate the necessary additionaltubing needed for recirculation. As will be understood, such bulky pullblocks and/or bulky inflation blocks would otherwise create difficultyduring pulling of the liner assembly into the pipeline, and duringwithdrawal of the liner assembly from the pipeline.

As will be appreciated, and as discussed above for steam generator 90,the steam-air mixture used to cure the tubular liner 44 is relativelylight in weight, which advantageously allows the liner assembly 20 to beused to repair or reinforce vertically-oriented sections of pipeline. Incontrast, prior art liner assemblies that use hot water to cure priorart tubular liners are not suitable for use in vertically-orientedsections of pipeline, due to the weight of the column of hot water.

As will be appreciated, the air heater 282 of the steam generator 90allows the air temperature to be controlled prior to combining withsteam. As will be understood, this feature advantageously providesimproved temperature control of the resulting steam-air mixture, ascompared to prior art systems that use only steam to cure epoxy.

As will be appreciated, the air heater 282 of the automated steamgenerator 222 enables the steam-air mixture to be generated using lessenergy to heat the water to generate steam. As will be understood, thisfeature advantageously allows the size of the water heater 94 (and inturn the size of the automated steam generator 222) to be reduced, ascompared to prior art steam generators that do not have an air heaterfor pre-heating air.

As will be appreciated, the small size of the automated steam generator222 enables it to be electrically powered by plugging into AC mains. Aswill be understood, this advantageously allows the automated steamgenerator 222 to be operated indoors, in contrast with prior art gas- ordiesel-powered steam generators for use with prior art pipeline repairsystems.

As will be appreciated, the portability of the automated steam generator222 allows the steam-air mixture to be generated near to the location ofthe pipeline to be repaired or reinforced, which advantageouslyeliminates the need for steam to otherwise be generated remotely and/orbe conveyed to the location of the pipeline via separate tubing. As willbe understood, the use of separate tubing for conveying suchremotely-generated steam would otherwise be tedious, and would otherwisecreate a safety hazard for workers at the location of the pipeline.

Although in the embodiment described above, a distal end temperaturesensor is positioned at the distal end of the liner assembly 20 adjacentthe relief valve 30, in other embodiments, there may alternatively be nodistal end temperature sensor used. In one such embodiment, theestimated curing time of the liner 42 may be calculated by theautomation application using at least: i) a calculated amount of totalheat required for curing, based on information entered by the user intothe pipe information input page 376; ii) the flow rate and flowtemperature, as measured by the air flow meter 268 and the outgoingtemperature sensor 286; and iii) the epoxy type, based on informationentered by the user into the job information input page 372.

In other embodiments, regardless of whether a distal end temperaturesensor is used, the estimated curing time of the liner 42 mayalternatively be calculated by the automation application using atleast: i) a calculated amount of total heat required for curing, basedon information entered by the user into the pipe information input page376; and ii) the flow rate and flow temperature, as measured by the airflow meter 268 and the outgoing temperature sensor 286.

The following example illustrates an application of above-describedembodiments.

Example 1

Flow rate testing was carried out by connecting a flow meter to theoutlet of the pressure relief valve of a liner assembly positioned in anexemplary four (4) inch diameter pipeline. The inflation block of theliner assembly was connected to a steam generator by an inflation line.The release pressure setting of the pressure relief valve was set tonear zero (0) psi by rotating the rotatable nut of the pressure reliefvalve to the end of the threaded travel. In this manner, the pressurerelief valve opened at all applied pressures. The pressure inside thebladder was controlled by adjusting the regulator valve of the steamgenerator.

Table 1 shows the flow rate of the steam-air mixture through the bladdermeasured at different pressure values.

TABLE 1 Measured Flow Rate Pressure (psi) (cfm, @ 4 in dia.) 5 3.1 104.7 15 5.9 20 7.2 25 8.4The results are shown graphically in FIG. 12. As can be seen, therelationship between flow rate and pressure was generally linear overthe pressure range used.

Example 2

Flow rate testing was carried out by connecting a flow meter to theoutlet of the pressure relief valve of a liner assembly positioned inexemplary three (3), four (4) and six (6) inch diameter pipelines. Theinflation block of the liner assembly was connected to the steamgenerator by an inflation line. The release pressure setting of thepressure relief valve was set to near zero (0) psi by rotating therotatable nut of the pressure relief valve to the end of the threadedtravel. In this manner, the pressure relief valve opened at all appliedpressures. The pressure inside the bladder was controlled by setting theregulator valve of the steam generator to a value of 17 psi.

Table 2 shows the flow rate of the steam-air mixture through the bladdermeasured for different pipeline diameters.

TABLE 2 Measured Flow Rate Diameter (in) (cfm, @ 17 psi) 3 6.0 4 6.0 66.1The results are shown graphically in FIG. 13. As can be seen, at a setpressure of 17 psi, the flow rate through the bladder was generallyconstant for the pipeline diameters tested.

Although embodiments have been described above with reference to theaccompanying drawings, those of skill in the art will appreciate thatvariations and modifications may be made without departing from thescope thereof as defined by the appended claims.

What is claimed is:
 1. A method of installing a liner assembly forpipeline repair or reinforcement, the method comprising: pulling aprepared liner assembly into position in the pipeline, the linerassembly including an outer tubular liner and an inner inflatablebladder positioned longitudinally within the tubular liner, the tubularliner being wetted with a curable compound; introducing fluid into theinflatable bladder so that the inflatable bladder expands to bring thetubular liner into firm contact with an interior surface of thepipeline; flowing the fluid continuously through the bladder anddischarging the fluid into the pipeline, while maintaining the linerassembly in an inflated condition for a time period sufficient for thetubular liner to cure; and deflating the inflatable bladder andretrieving at least a portion of the liner assembly from the pipeline.2. The method of claim 1, wherein the fluid comprises a mixture of steamand air.
 3. The method of claim 2, further comprising heating the airprior to combining the air with the steam.
 4. The method of claim 1,further comprising increasing a temperature of the inflatable bladderand the tubular liner by increasing a flow rate of fluid through theliner assembly in the inflated condition.
 5. The method of claim 4,wherein increasing the flow rate comprises one or both of: increasingpressure of the fluid introduced into the inflatable bladder; andincreasing a discharge rate of the fluid into the pipeline.
 6. Themethod of claim 5, wherein increasing the discharge rate of the fluidinto the pipeline comprises reducing a release pressure setting of apressure relief valve connected to an end of the inflatable bladder. 7.The method of claim 1, wherein the time period comprises: a first timeperiod during which a first fluid is flowed through the bladder, thefirst fluid being a steam-air mixture, and a second time period duringwhich a second fluid is flowed through the bladder.
 8. The method ofclaim 7, wherein the second fluid is air at ambient temperature.
 9. Themethod of claim 7, wherein the second fluid comprises no steam or lesssteam than the first fluid.
 10. The method of claim 7, wherein thehardness of the tubular liner increases during the second time period.11. The method of claim 7, wherein the temperatures of the inflatablebladder and the tubular liner decrease during the second time period.12. A liner assembly for a pipeline section, the liner assemblycomprising: an outer tubular liner; an inner inflatable bladderpositioned longitudinally within the tubular liner; an inflation blockconnected to a first end of the inflatable bladder, the inflation blockhaving a nozzle for receiving a fluid comprising steam; and a pull blockconnected to a second end of the inflatable bladder, the pull blockhaving a fluid discharge outlet.
 13. The liner assembly of claim 12,wherein the fluid discharge outlet is a pressure relief valve.
 14. Theliner assembly of claim 13, wherein the pressure relief valve is anin-line pressure relief valve.
 15. A steam generator for use with aliner assembly for pipeline repair or reinforcement, the steam generatorcomprising: a water heater configured to heat water to generate steam; awater feed conduit configured to convey water to the water heater; anair heater configured to generate heated air; an air supply conduitconfigured to convey pressurized air to the air heater; a heated airsupply conduit configured to convey heated air from the air heater tothe water heater to yield a steam-air mixture; and an output conduitconfigured to convey the steam-air mixture from the water heater. 16.The steam generator of claim 15, further comprising a flow meter influid communication with the air supply conduit.
 17. The steam generatorof claim 16, wherein the flow meter is configured to output a signalindicating a flow rate of the pressurized air.
 18. The steam generatorof claim 15, wherein the steam generator is sized to be transported by asingle individual.
 19. The steam generator of claim 15, wherein thewater heater comprises one or more electrically-powered heatingelements.
 20. The steam generator of claim 15, wherein the air heatercomprises one or more electrically-powered heating elements.